"I am NOT suggesting the Serapeum boxes themselves were man made (stone) NOR geopolymer"
My caution about the geopolymer theory definitely increases when it comes to igneous, but I do think there was something going on with igneous rock as well. Just gotta be more careful to identify which is which between megalithic work around the world so I can at least figure out the distinction of common elements of those works.
Its not sexy to think of this work having been coated with a sealant, but those drips are pretty clearly THAT material, as opposed to drips of actual melted/softened rock. The images of 'vitrification' chipping off various places around the world I suppose could be that sealant, having bonded to the surface and come off, but it feels like a leap to assume it was that strong to have created a hardened shell around what is already hard granite and chipped off. It implies the sealant is harder than granite, and that seems ridiculous.
The idea of using a sealant makes sense at least for the Canadian climate considering the damage moisture can do seeping into micro cracks and inclusions and then expanding and contracting with such a wide range of temperature change. But these places are equatorial. Ice age?
Put another 'need to study' on the list as far as those drips on the serapeum box. Somebody needs to grab a sample and get it under a microspectrometer.